A December article in The New York Times brought the trend of drinking "unfiltered, untreated, un-sterilized spring water" into the national consciousness. In San Francisco, the report explained, the co-up Rainbow Grocery was selling 2.5 gallons of the stuff bottled by start-up Live Water for $36.99.

Since the report, Live Water has increased the price. According to what the co-up told Business Insider, the bottled water now costs $38.49. Refills go for $16.49, up from $14.99.

Sales of the raw water have also surged, according to Live Water's website.

"First Water Delivery Might Take Longer Than Usual -- New Orders Will Be Delivered In The Order They Are Received," the company's website says.

Although the new trend has its proponents, mainly those leery of fluoride and contamination from lead or other issues, experts have come out strongly against the idea.

"When water isn't treated, it can contain chemicals and germs that can make us sick or cause disease outbreaks," Vince Hill, chief of the CDC's Waterborne Disease Prevention Branch, told Time.

"Anything you can think of can be in untreated water," he added, mentioning agricultural runoff, naturally occurring chemicals, bacteria and viruses.

Bill Marler, a food-safety advocate and attorney said that: "almost everything conceivable that can make you sick can be found in (untreated) water."

Among other harmful bacteria and diseases, untreated water can contain cholera, E. coli, hepatitis A, and giardiasis. As for fluoride concerns, experts say that as long as the chemical is added properly, humans can only see benefits.

Vincent Casey, a senior water sanitation and hygiene manager at clean water nonprofit WaterAid, explained that the levels of fluoride found in normal drinking water throughout the country are not dangerous. Problems only occur when high concentrations of the chemical are present.

"In low quantities, it is scientifically proven that (fluoride) is beneficial to dental health," Casey said.

"If a water company or a utility is carrying out its treatment to the right standards, there shouldn't be instances where these concentrations are going to hazardous levels at all," he said.

But, Mukhande Singh, the founder of Live Water, whose marketing materials feature him cross-legged and naked at a hot spring, says the goal is not pristine water.

"You're going to get 99 percent of the bad stuff out (if you use a filter)," Singh admitted. "But now you have dead water."

According to him, "real water" has an expiration date. "It stays most fresh within one lunar cycle of delivery," he said. "If it sits around too long, it'll turn green. People don't even realize that because all their water's dead, so they never see it turn green."

Singh also believes public water has been "poisoned."

"Tap water? You're drinking toilet water with birth control drugs in them," he said. "Chloramine, and on top of that they're putting in fluoride. Call me a conspiracy theorist, but it's a mind-control drug that has no benefit to our dental health."

Of course, it must be noted that there isn't any scientific evidence that fluoride is linked to mind control. However, as Casey said, it has been scientifically proven to benefit dental health in low quantities.

Despite the scientific viewpoint, other raw water startups have cropped up. Untreated water was sold at Burning Man by Doug Evans, the man behind the failed juicing company, Juicero, which collapsed in September.

While the fad may have found a viable market, experts are simply left scratching their heads.

"Without water treatment, there's acute and then chronic risks," said Dr. Donald Hensrud the director of the Healthy Living Program at the Mayo Clinic in Rochester, Minnesota.

"There's evidence all over the world of this, and the reason we don't have those conditions is because of our very efficient water treatment," he said.